Explain cloud computing characteristics and uses

Communications Technology – Cloud Computing

Learning Objective

Explain the key characteristics of cloud computing and describe its common uses in business, personal and societal contexts.

What is Cloud Computing?

Cloud computing is the delivery of computing resources – hardware, software, storage and services – over the Internet on a pay‑as‑you‑go basis. Users access these resources remotely, without owning or managing the underlying infrastructure.

Core Characteristics (Syllabus 14.4)

• On‑demand self‑service – Users can provision, configure and release resources automatically, without human interaction with the provider.
• Broad network access – Services are reachable over the network using standard mechanisms (web browsers, mobile apps, APIs) and across a range of devices.
• Resource pooling – The provider’s physical resources are pooled to serve multiple customers using a multi‑tenant model; each consumer’s resources are dynamically assigned and isolated.
• Measured service – Resource usage is monitored, controlled and billed per unit (e.g., CPU‑hours, GB‑storage, bandwidth).
• Reliability & availability – Redundant infrastructure, fault‑tolerant designs and geographically dispersed data centres aim to provide high uptime and rapid recovery.
• Elasticity (Scalability) – Resources can be automatically scaled up or down to match changing demand, ensuring efficient use of the pooled infrastructure.

Link to Networking (OSI / TCP‑IP)

Cloud services are delivered over the Internet protocol stack. The typical flow is shown below:

• SaaS → HTTP/HTTPS (OSI Layer 7 – Application)
• PaaS / IaaS APIs → RESTful or SOAP over TCP (Layer 4 – Transport) → IP (Layer 3 – Network) → Ethernet / Wi‑Fi (Layer 2 – Data Link) → Physical media (Layer 1 – Physical)

These protocols enable devices of any type (desktop, tablet, smartphone) to communicate with cloud data centres located anywhere in the world.

Service Models

Deployment Models

1. Public cloud – Services offered over the public Internet and shared among many organisations (e.g., Amazon Web Services, Microsoft Azure).
2. Private cloud – Cloud infrastructure operated solely for a single organisation, either on‑premises or hosted.
3. Hybrid cloud – Combination of public and private clouds, allowing data and applications to move between them.
4. Community cloud – Shared by several organisations with common concerns such as security, compliance or research goals.

Common Uses of Cloud Computing

• Data storage & backup – Amazon S3, Google Drive.
• Collaboration & productivity – Microsoft Teams, Slack, Google Workspace.
• Streaming media – Netflix, Spotify.
• Big‑data analytics – Azure HDInsight, Google BigQuery.
• Internet of Things (IoT) platforms – AWS IoT Core, Azure IoT Hub.
• Virtual desktops – Amazon WorkSpaces, Citrix Cloud.

Case Study – Education (Societal Use)

Scenario: A secondary school adopts Google Workspace for Education. All teachers and pupils access Gmail, Docs, Slides and Classroom from any device with an Internet connection. The school benefits from:

• Zero capital cost for servers – the service is SaaS, paid per user per year.
• Scalability – during exam periods the platform automatically handles higher traffic (elasticity).
• Collaboration – real‑time editing of documents supports group projects.
• Data protection – Google encrypts data at rest and in transit and complies with GDPR, giving the school a clear privacy framework.

This example demonstrates a societal benefit (enhanced learning) while linking directly to the syllabus points on characteristics, advantages and security.

Advantages for Businesses & Individuals

• Reduced capital expenditure (CAPEX) – pay only for what you use.
• Scalability & elasticity – resources can be expanded or reduced instantly to match demand.
• Speed of deployment – new services can be launched within minutes.
• Support for remote working and global collaboration.
• Access to advanced technologies (AI, analytics, serverless computing) without large upfront investment.

Potential Drawbacks (including Societal & Environmental Impact)

• Dependence on reliable Internet connectivity.
• Security & privacy – data stored off‑site may be vulnerable; mitigation includes encryption (at rest & in transit), strong identity‑management, multi‑factor authentication and compliance with regulations such as GDPR.
• Vendor lock‑in – migration between providers can be complex and costly.
• Variable performance due to shared resources (the “noisy neighbour” effect).
• Environmental impact – Large data centres consume significant electricity; many providers now use renewable energy and improve cooling efficiency.
• Digital divide – Unequal access to high‑speed Internet can limit the benefits of cloud services for some communities.

Example Calculation – Pay‑per‑Use Cost

Suppose a company runs a virtual machine that costs $0.10 per hour. If it runs for 150 hours in a month, the cost is:

Cost = 0.10 × 150 = $15.00

Summary

Cloud computing provides flexible, scalable and cost‑effective resources through well‑defined service and deployment models. Its six key characteristics – on‑demand self‑service, broad network access, resource pooling, measured service, reliability/availability and elasticity – underpin the advantages and challenges outlined above. Understanding these concepts enables learners to evaluate when and how cloud solutions should be used, both in business and in wider society.